| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve the accuracy of diagnosing a failure of a supercharger of an engine with the supercharger. <P>SOLUTION: When a throttle valve is closed during the operation of the engine, an air bypass valve (ABV) in an intake bypass line for bypassing a compressor of the supercharger is temporarily opened for releasing supercharging pressure between the compressor and the throttle valve to prevent surging. In this case, a variation in the rotating speed of the compressor is detected before and after changing over the air bypass valve from an open position to a close position, and the presence or not of the failure of the supercharger is diagnosed in accordance with the variation of the rotating speed of the compressor. Herein, a correlation exists between the rotating speed of the compressor and each of the supercharging pressure, intake pipe pressure and an intake air amount, and so the rotating speed of the compressor can be estimated in accordance with at least one of the supercharging pressure, the intake pipe pressure and the intake air amount. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
